The more persons would be behind the Satoshi identity, the more chances there would be for mistakes or leaks: one of them spending/stealing the BTC, one of them boasting about the secret Bitcoin project, or revealing it while intoxicated at a party, etc.
This doesn't have to be some crazy story. There's the means, the motive, and the opportunity to create Bitcoin. Why would a lone actor be so motivated to keep their identity a secret?
We obviously disagree.
There are 2 simple reasons why Satoshi would want to remain anonymous:
#1 He is estimated to own ~1 million BTC ($200 million); many thieves would capture/torture/murder someone for the chance to steal that amount!
#2 Sometimes people just want anonymity by default, like you who posts anonymously for no apparent reason ;)
Bitcoin will not be outlawed by the US or Europe. China seems like the only remaining threat as far as outlawing Bitcoin.